Slide 2 2.5 Cell Division How you got from one to trillions!!
Slide 3 Conception All animals begin as a fertilised egg cell (a
zygote) Image Credit: ZygoteZygote Slide 4 Then it divides Image
Credit: www.ehd.org/www.ehd.org/ Slide 5 and divides Released into
the Public Domain by JrockleyJrockley Slide 6 Until it becomes an
embryo Image Credit:
www.scienceclarified.comwww.scienceclarified.com Slide 7 Cell Cycle
Interphase Longest phase (94%) G1: Cell growth S: Replication of
DNA G2: Growth for division of cell Mitosis Division of nucleus and
chromosomes Cytokinesis Division of cytoplasm and organelles into
two daughter cells. 2.5.1 Slide 8 Cell cycles are not uniform Cell
typeCell cycle / h Bean root tip19.3 Mouse fibroblast22 Chinese
hamster fibroblast11 Mouse small intestine epithelium 17 Mouse
esophagus epithelium181 2010 Paul Billiet ODWSODWS Slide 9 Mitosis
Cell Basics Somatic (body) cells. Diploid (2n): one chromosome from
each parent. (n=23) Duplicated chromosomes have 2 sister
chromatids. Attached at centromere in the middle. Both are called
chromosomes!! Slide 10 Mitosis Responsible for cellular: Growth
Embryonic development Tissue repair Asexual Reproduction 2.5.6
Slide 11 Interphase Active period. Many metabolic reactions occur,
including protein synthesis. Increase in number of mitochondria
and/or chloroplasts. Most important: DNA replication while
chromatin. S phase. 2.5.3 Slide 12 Interphase Slide 13 Prophase
Preparing. Supercoiling of chromosomes (condense) Nuclear membrane
and nucleolus disappear. 2.5.4 Slide 14 Prophase Slide 15 Metaphase
Meet in the Middle. Attachment of spindle microtubules to
centromeres, one from each centriole. All chromosomes are lined up
at the middle, also called the equator. Equal pulling from opposite
ends. 2.5.4 Slide 16 Metaphase Slide 17 Anaphase Moving away
Centromeres split. Sister chromatids are pulled to opposite poles
by spindle fibers. Each is now considered a chromosome. Two diploid
cells are forming. 2.5.4 Slide 18 Anaphase Slide 19 Telophase Two
nuclei. Chromosomes change to chromatin. Nuclear membrane reforms.
New nucleoli form. Cytokinesis is usually happening at the same
time as telophase. 2.5.4 Slide 20 Telophase Slide 21 Cytokinesis
Cell membrane and cytoplasm division. Two genetically identical
nuclei now found in two diploid daughter cells. 2.5.5
